Crank handles are among the oldest of simple mechanical devices, having been used for thousands of purposes over thousands of years. Such devices are used for turning something about a main axis. The crank handles themselves typically extend along an axis substantially parallel to and offset from the main axis.
Despite the antiquity of crank handles in general, improvements in crank handle apparatus continue to be made. And, there remains a need for improvement in crank handle construction.
Crank handles for inexpensive devices, such as drain-cleaning augers, have a number of drawbacks. First, in many cases crank handles for inexpensive devices include handle members which are non-rotatably affixed to the rod on which they are mounted. This has obvious drawbacks when it comes to ease of operation. Other crank handle apparatus for such inexpensive devices, while having rotatably mounted handles, are themselves somewhat costly in that three or more parts are included and a number of steps are required for assembly.
In some cases, a part as simple as a friction cap or nut (for example, what is known as a "pal nut") or some other kind of nut or attachment device is secured to the end of a rod protruding through a handle member. This is done to keep the handle from falling off the rod on which it is rotatably disposed. This sort of construction requires an assembly step which may be time-consuming and which, if carried out inaccurately as can often happen, leads to the need for later replacement.
Devices of this type, even when properly assembled, can have a tendency to require later replacement or service. This is particularly the case for devices which undergo much abuse during their normal use. A good example is drain-cleaning augers, the handles of which have substantial and irregular forces applied to them in various directions. This can loosen and knock a friction nut off the end of the rod to which it is attached.
A construction which eliminates the friction cap or nut often means losing rotatability of the handle on the rod, as previously noted. This is often unacceptable. There is a need for an improved, reliable, less-costly, easily assembled crank hand apparatus which is useful for inexpensive devices which undergo much abuse.